You can determine the rate of calcification at any given carbonate ion concentration as follows: draw a vertical line up from the x-axis at that concentration value until it intersects the red linear regression line; then draw a horizontal line from the intersection over to the y-axis to see what the calcification rate is at that carbonate ion concentration. if the seawater carbonate ion (co3 2-) concentration is 270 µmol/kg,
a. what is the approximate rate of calcification, and
b. approximately how many days would it take 1 square meter of reef to accumulate 30 mmol of calcium carbonate (caco3)